initial commit

maps/maps.go

@@ -0,0 +1,57 @@
+package main
+
+import (
+	"fmt"
+	"maps"
+)
+
+func main() {
+	// to create an empty map, use the builtin make:
+	// make(map[key-type]val-type)
+	m := make(map[string]int)
+
+	//set key/value pairs using typical name[key] = val syntax
+	m["k1"] = 7
+	m["k2"] = 13
+
+	// printing a map with e.g.
+	// fmt.Println will show all of its key/value pairs
+	fmt.Println("map:",m)
+
+	// Get a value from a key with name[key]
+	// if the key doesn't exist the zero value of the value type is returned
+	
+	v1 := m["k1"]
+	fmt.Println("v1:",v1)
+
+	v3 := m["k3"]
+	fmt.Println("v3:",v3)
+
+	//the builtin len returns the number of key/value pairs when called on a map
+	fmt.Println("len:", len(m))
+
+	//the builtin delete removes key/value pairs from a map,
+	//use the clear builtin to remove all key/value pairs from a map.
+	delete(m, "k2")
+	fmt.Println("map:",m)
+
+	clear(m)
+	fmt.Println("map:",m)
+
+	// the optional second return value when getting the value
+	// from a map indicates if the key was present in the map allowing
+	// to diferentiate between default zero-values and values acutally stored as 0
+	// here we dont need the value itself so we ignore it with the _ or blank identifier
+	_, prs := m["k2"]
+	fmt.Println("prs:",prs)
+
+	//you can declare and initalize a new map in the same line with the following syntax:
+	n := map[string]int{"foo": 1,"bar": 2}
+	fmt.Println("map:", n)
+
+	//the map package also contains useful funcs for map such as .Equal
+	n2 := map[string]int{"foo": 1,"bar":2}
+	if maps.Equal(n,n2){
+		fmt.Println("n == n2")
+	}
+}